Change the ibm-config flag to sync-mac

- As per the commit merged in phosphor-networkd, the ibm-config
  flag is now changed to sync-mac.

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: I2ff7acf05358d82a4803097e694c1d50ad344f98
diff --git a/recipes-phosphor/network/phosphor-network_%.bbappend b/recipes-phosphor/network/phosphor-network_%.bbappend
index 76e440b..150d373 100644
--- a/recipes-phosphor/network/phosphor-network_%.bbappend
+++ b/recipes-phosphor/network/phosphor-network_%.bbappend
@@ -4,7 +4,7 @@
 SYSTEMD_SERVICE_${PN} += " ncsi-netlink.service"
 FILES_${PN} += "${datadir}/network/*.json"
 
-EXTRA_OECONF += "--enable-ibm-config"
+EXTRA_OECONF += "--enable-sync-mac"
 
 install_network_configuration(){
     install -d ${D}${systemd_system_unitdir}